Hadoop mapreduce-java.io.IOException:作业失败
我在尝试执行Hadoop mapreduce-java.io.IOException:作业失败,java,hadoop,Java,Hadoop,我在尝试执行hadoopmapreduce程序时遇到以下异常 java.io.IOException:作业失败! 位于org.apache.hadoop.mapred.JobClient.runJob(JobClient.java:865) 位于com.vasa.books.BookDriver.main(BookDriver.java:37) BookDriver.java package com.vasa.books; import org.apache.hadoop.fs.Path; i
hadoop
mapreduce
程序时遇到以下异常
java.io.IOException:作业失败!
位于org.apache.hadoop.mapred.JobClient.runJob(JobClient.java:865)
位于com.vasa.books.BookDriver.main(BookDriver.java:37)
BookDriver.java
package com.vasa.books;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.io.IntWritable;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.mapred.FileInputFormat;
import org.apache.hadoop.mapred.FileOutputFormat;
import org.apache.hadoop.mapred.JobClient;
import org.apache.hadoop.mapred.JobConf;
import org.apache.hadoop.mapred.TextInputFormat;
import org.apache.hadoop.mapred.TextOutputFormat;
public class BookDriver {
public static void main(String args[]) {
// TODO Auto-generated method stub
JobClient client=new JobClient();
JobConf conf=new JobConf(com.vasa.books.BookDriver.class);
conf.setJobName("booknamefind");
conf.setOutputKeyClass(Text.class);
conf.setOutputValueClass(IntWritable.class);
conf.setMapperClass(com.vasa.books.bookmapper.class);
conf.setReducerClass(com.vasa.books.bookreducer.class);
conf.setInputFormat(TextInputFormat.class);
conf.setOutputFormat(TextOutputFormat.class);
FileInputFormat.setInputPaths(conf,new Path(args[0]));
FileOutputFormat.setOutputPath(conf, new Path(args[1]));
client.setConf(conf);
try{
JobClient.runJob(conf);
}catch(Exception e){
e.printStackTrace();
}
}
}
package com.vasa.books;
import java.io.IOException;
import org.apache.hadoop.io.IntWritable;
import org.apache.hadoop.io.LongWritable;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.io.Writable;
import org.apache.hadoop.io.WritableComparable;
import org.apache.hadoop.mapred.MapReduceBase;
import org.apache.hadoop.mapred.Mapper;
import org.apache.hadoop.mapred.OutputCollector;
import org.apache.hadoop.mapred.Reporter;
public class BookMapper extends MapReduceBase implements Mapper<LongWritable,Text,Text,IntWritable> {
private final static IntWritable one=new IntWritable(1);
public void map(LongWritable _key, Text value,
OutputCollector<Text, IntWritable> output, Reporter reporter)
throws IOException {
// TODO Auto-generated method stub
String Tempstring=value.toString();
String[] singlebookdata=Tempstring.split("\",\"");
output.collect(new Text(singlebookdata[3]), one);
}
}
BookMapper.java
package com.vasa.books;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.io.IntWritable;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.mapred.FileInputFormat;
import org.apache.hadoop.mapred.FileOutputFormat;
import org.apache.hadoop.mapred.JobClient;
import org.apache.hadoop.mapred.JobConf;
import org.apache.hadoop.mapred.TextInputFormat;
import org.apache.hadoop.mapred.TextOutputFormat;
public class BookDriver {
public static void main(String args[]) {
// TODO Auto-generated method stub
JobClient client=new JobClient();
JobConf conf=new JobConf(com.vasa.books.BookDriver.class);
conf.setJobName("booknamefind");
conf.setOutputKeyClass(Text.class);
conf.setOutputValueClass(IntWritable.class);
conf.setMapperClass(com.vasa.books.bookmapper.class);
conf.setReducerClass(com.vasa.books.bookreducer.class);
conf.setInputFormat(TextInputFormat.class);
conf.setOutputFormat(TextOutputFormat.class);
FileInputFormat.setInputPaths(conf,new Path(args[0]));
FileOutputFormat.setOutputPath(conf, new Path(args[1]));
client.setConf(conf);
try{
JobClient.runJob(conf);
}catch(Exception e){
e.printStackTrace();
}
}
}
package com.vasa.books;
import java.io.IOException;
import org.apache.hadoop.io.IntWritable;
import org.apache.hadoop.io.LongWritable;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.io.Writable;
import org.apache.hadoop.io.WritableComparable;
import org.apache.hadoop.mapred.MapReduceBase;
import org.apache.hadoop.mapred.Mapper;
import org.apache.hadoop.mapred.OutputCollector;
import org.apache.hadoop.mapred.Reporter;
public class BookMapper extends MapReduceBase implements Mapper<LongWritable,Text,Text,IntWritable> {
private final static IntWritable one=new IntWritable(1);
public void map(LongWritable _key, Text value,
OutputCollector<Text, IntWritable> output, Reporter reporter)
throws IOException {
// TODO Auto-generated method stub
String Tempstring=value.toString();
String[] singlebookdata=Tempstring.split("\",\"");
output.collect(new Text(singlebookdata[3]), one);
}
}
package com.vasa.books;
导入java.io.IOException;
导入org.apache.hadoop.io.IntWritable;
导入org.apache.hadoop.io.LongWritable;
导入org.apache.hadoop.io.Text;
导入org.apache.hadoop.io.writeable;
导入org.apache.hadoop.io.WritableComparable;
导入org.apache.hadoop.mapred.MapReduceBase;
导入org.apache.hadoop.mapred.Mapper;
导入org.apache.hadoop.mapred.OutputCollector;
导入org.apache.hadoop.mapred.Reporter;
公共类BookMapper扩展MapReduceBase实现Mapper{
私有最终静态IntWritable one=新的IntWritable(1);
public void映射(LongWritable\u键、文本值、,
OutputCollector输出,报告器(报告器)
抛出IOException{
//TODO自动生成的方法存根
字符串Tempstring=value.toString();
String[]singlebookdata=Tempstring.split(“\”,“\”);
output.collect(新文本(singlebookdata[3]),一个);
}
}
为什么会出现这种异常?根据JobClient源代码,JobClient.runJob()
调用JobClient.monitorAndPrintJob()
,返回布尔值。如果该布尔值为false(表示作业失败),它将打印出您看到的无用错误消息“something failed!”
要解决此问题,您有两种选择:
1-(更快)检查日志。RunningJob
故障信息应打印到日志中
2-如果您不知道日志在哪里,没有启用日志记录,或者不想挖掘日志,您可以重写一点代码。与使用JobClient.runJob()
不同,我将在代码中执行与runJob()
相同的操作,以便在失败时获得有用的错误消息
public static RunningJob myCustomRunJob(JobConf job) throws Exception {
JobClient jc = new JobClient(job);
RunningJob rj = jc.submitJob(job);
if (!jc.monitorAndPrintJob(job, rj)) {
throw new IOException("Job failed with info: " + rj.getFailureInfo());
}
return rj;
}
我猜根本的问题是找不到arg[0]或arg[1](您的输入或输出文件) 您能显示您给定的参数吗?@patrick在运行配置中,我已将以下参数作为输入和输出BX-Books.txt out_文件检查此文件的路径是否正确。在您的参数中,路径应该正好是文件存储的位置。感谢ur suggession@aguibert,最后我发现异常是由于我在BookMapper.java中拆分文本文件的方式造成的